package com.ai.wx.util; 

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Formatter;
import java.util.UUID;

import org.apache.commons.lang.RandomStringUtils;

import com.ai.core.util.Configure;
import com.ai.wx.pojo.JsSign;

/**
 * 请求校验工具类
 * 
 * @author liufeng
 * @date 2013-05-18
 */
public class SignUtil {
	// 与接口配置信息中的Token要一致
	private static String token = Configure.getString("token");

	/**
	 * 验证签名
	 * 
	 * @param signature
	 * @param timestamp
	 * @param nonce
	 * @return
	 */
	public static boolean checkSignature(String signature, String timestamp, String nonce) {
		String[] arr = new String[] { token, timestamp, nonce };
		// 将token、timestamp、nonce三个参数进行字典序排序
		Arrays.sort(arr);
		StringBuilder content = new StringBuilder();
		for (int i = 0; i < arr.length; i++) {
			content.append(arr[i]);
		}
		MessageDigest md = null;
		String tmpStr = null;

		try {
			md = MessageDigest.getInstance("SHA-1");
			// 将三个参数字符串拼接成一个字符串进行sha1加密
			byte[] digest = md.digest(content.toString().getBytes());
			tmpStr = byteToStr(digest);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}

		content = null;
		// 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
		return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
	}

	
	public static JsSign getJsSignature(String jsapiTicket, String url) throws UnsupportedEncodingException {
		long timestamp = System.currentTimeMillis() / 1000;
		String nonce = UUID.randomUUID().toString();
		String string1 = "jsapi_ticket="+jsapiTicket+"&noncestr="+nonce+"&timestamp="+timestamp+"&url="+url;
		MessageDigest md = null;
		JsSign sign = new JsSign();
		sign.setTimestamp(timestamp);
		sign.setNonce(nonce);
		sign.setJsapiTicket(jsapiTicket);
		sign.setUrl(url);
		try {
			
			MessageDigest crypt = MessageDigest.getInstance("SHA-1");
            crypt.reset();
            crypt.update(string1.getBytes("UTF-8"));
            String signature = byteToHex(crypt.digest());

			sign.setSignature(signature); ; 
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		return sign;
	}


    private static String byteToHex(final byte[] hash) {
        Formatter formatter = new Formatter();
        for (byte b : hash)
        {
            formatter.format("%02x", b);
        }
        String result = formatter.toString();
        formatter.close();
        return result;
    }
	
	public static long getTimestamp(){
		long timeStamp = System.currentTimeMillis();
		return timeStamp;
	}
	
	public static String getNonceStr(){
		return RandomStringUtils.randomAlphanumeric(20);
	}
	
	/**
	 * 将字节数组转换为十六进制字符串
	 * 
	 * @param byteArray
	 * @return
	 */
	private static String byteToStr(byte[] byteArray) {
		String strDigest = "";
		for (int i = 0; i < byteArray.length; i++) {
			strDigest += byteToHexStr(byteArray[i]);
		}
		return strDigest;
	}

	/**
	 * 将字节转换为十六进制字符串
	 * 
	 * @param mByte
	 * @return
	 */
	private static String byteToHexStr(byte mByte) {
		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
		char[] tempArr = new char[2];
		tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
		tempArr[1] = Digit[mByte & 0X0F];

		String s = new String(tempArr);
		return s;
	}
}
